UCSC experiments give hope for endangered plant

Santa Cruz >> A critically endangered plant known as marsh sandwort is inching back from the brink of extinction thanks to efforts of a UC Santa Cruz plant ecologist and her team of undergraduate students.

Ingrid Parker, the Langenheim professor of plant ecology and evolution at UCSC, got involved in the recovery of marsh sandwort, formally known as Arenaria paludicola, at the request of the U.S. Fish and Wildlife Service, which funded the research.

Although it used to occur all along the west coast, the wetland plant with delicate white flowers had dwindled to one population in a boggy wetland in San Luis Obispo County. Federal biologists wanted to reintroduce the plant to other locations but weren't sure where it would be likely to thrive.

"When you have a species that's only known from one place, how do you figure out where it could live?" Parker asked. "We had very little information about its biology that would allow us to predict where it might be successful."

Her team, which included undergraduate students and greenhouse staff at UCSC as well as USFWS biologists, propagated cuttings from the last remaining wild population, studied the plant's tolerance for different soil conditions in greenhouse experiments, and conducted field experiments to identify habitats where the plant could thrive. They published their findings in the April issue of Plant Ecology.

Surprisingly, the plants tolerated a much wider range of soil moisture and salinity than biologists had expected.

"This really brought home to me the importance of experiments to help guide conservation," Parker said. "The one place where this species is found in San Luis Obispo County is a freshwater bog where the plants are in standing water. There are so few places like that left in California, we wondered if that's the only kind of place where it can grow. Instead we found that it actually does better without standing water."

In addition, field studies showed the importance of small-scale habitat variations, according to first author Megan Bontrager.

"We planted out marsh sandwort in different habitats within a stone's throw of each other, and in areas dominated by willow they all died, whereas we had good success in nearby areas dominated by different species," said Bontrager, who worked on the study as a UCSC undergraduate and is now a graduate student at the University of British Columbia.

A key finding was the discovery that a relatively common plant can serve as a useful indicator of good habitat for the endangered marsh sandwort. Water parsley, or Oenanthe sarmentosa, is a native plant that grows in wet areas along the west coast. Field experiments in two California State Parks in Santa Cruz County showed marsh sandwort does well in areas dominated by water parsley.

The researchers were thrilled to discover plants in the reintroduced populations are flowering and setting seed. This is important because sexual reproduction has not been observed in the one remaining natural population.

Tim Stephens is a science and engineering publicist for UC Santa Cruz.